MPU 6000 - Complementary Filter and DMP

Hi

I am using PIC32 with MPU6000 and Embedded Motion Driver 5.1
I am having a problem of drift on roll and pitch when I apply vibrations to my sensor. I am planning to use this sensor on device that will produce a significant number of vibrations. I have implemented complementary filter just by using the raw values and there is no drift, unfortunately when I have used quaternions from DMP and functions provided by the library to calculate the Euler angles there is a drift on these axis over a short period of time when vibration is applied.
Can someone help me why quaternions that supposed to be calibrated internally are not accurate and for that reason I notice drift?

Thanks for any help